A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

A federal judge sentenced a former Arkansas judge Wednesday to five years in prison — a stiffer punishment than prosecutors recommended — after he admitted giving young male defendants lighter sentences in return for personal benefits that included sexual favours.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

In a 60 Minutes online exclusive, reporter Liz Hayes quizzed Australian Prime Minister Malcolm Turnbull on his relationship with the unpredictable Twitter aficionado and US president Donald Trump ahead of their meeting at the White House Friday.

Union worried about WA police redundancies

Police in Western Australia may not be able to retain their current level of frontline service with the loss of nearly 200 experienced officers, the state's police union has warned.

The government and police commissioner Karl O'Callaghan revealed on Tuesday almost 200 police officers are set to quit the West Australian force under a voluntary severance scheme designed to put more police on the streets.

Police Minister Liza Harvey says the government had approved terms to release 196 highly-experienced officers who are no longer fit for frontline duties, but union vice president Brandon Shortland said that means a force already stretched to the limit could suffer.

"The community want police to be looking after them, but in this current industrial climate they are going to have trouble attracting and retaining the police they currently have," Mr Shortland said.

"WA police are at their limits in almost every operational aspect at the moment. It is going to be a very tough ask to retain frontline services with what they already have."

The severance payouts are set to cost about $37 million and will come from the police budget.

Commissioner O'Callaghan admitted the WA police training facilities would have to work "double-time" to keep up with demand to replace the retiring officers.